POLY4 Chlorophyll-a MODIS-Aqua Data in the Northwest Atlantic, 2002-present

Chlorophyll-a concentration (Chl-a) is used as a proxy for phytoplankton biomass to track blooms and monitor the state of the ecosystem. This dataset contains daily satellite Chl-a from July 2002 to July 2023 (further updates will be provided periodically). The data is at a 4.64-km^2 spatial resolution covering an area of the Northwest Atlantic from 39-82°N, 42-95°W. Chl-a was generated by applying the POLY4 algorithm (Clay et al., 2019, see resources) on level-3 binned remote sensing reflectance (Rrs) data retrieved by the Moderate Resolution Imaging Spectroradiometer sensor (MODIS) onboard the Aqua satellite, freely downloaded courtesy of NASA's Ocean Biology Processing Group (OBPG, https://oceancolor.gsfc.nasa.gov/). Regionally-tuned coefficients for POLY4 were generated by matching level-2 MODIS-Aqua pixels (i.e. individual satellite passes) to in situ HPLC (High Performance Liquid Chromatography) Chl-a samples within the region of interest according to the procedure described in Clay et al. POLY4 Chl-a was then optimized by simultaneously forcing it to the 1:1 line against in situ Chl-a to reduce the negative bias observed in higher concentrations. The Chl-a data were then projected onto an Equidistant Cylindrical grid (4.64-km^2) using a weighted mean for overlapping bins. This model and the Northwest Atlantic coefficients are available in the R package oceancolouR (https://github.com/BIO-RSG/oceancolouR).

Access and Use

Licence: Open Government Licence 2.0 (Canada)

Data and Resources

Citation

Keywords

Dataset extent

Metadata Reference Date(s) February 27, 2024 (Publication)
February 27, 2024 (Revision)
Data Reference Date(s) July 04, 2002 (Creation)
Frequency of Update As Needed

Responsible Party 1
Name
Clay, Stephanie ORCID logo
Affiliation
Fisheries and Oceans Canada ROR logo
Email
Stephanie.Clay@dfo-mpo.gc.ca
Role
  • Custodian
  • Distributor
  • Owner
Responsible Party 2
Name
Devred, Emmanuel ORCID logo
Affiliation
Fisheries and Oceans Canada ROR logo
Email
Emmanuel.Devred@dfo-mpo.gc.ca
Role
  • Distributor
  • Owner

Field Value
Ocean Variables
  • Phytoplankton biomass and diversity
  • Ocean colour
Scope Dataset
Status On Going
Maintenance Note Generated from https://cioos-siooc.github.io/metadata-entry-form
Spatial Extent [[[-95.0, 39.0], [-42.0, 39.0], [-42.0, 82.0], [-95.0, 82.0], [-95.0, 39.0]]]
North Bounding Latitude 82.0
South Bounding Latitude 39.0
East Bounding Longitude -42.0
West Bounding Longitude -95.0
Temporal Extent
Begin
2002-07-04
Vertical Extent
Min
0.0
Max
0.0
Default Locale English
Included in Data Catalogue
Included in Data Catalogue 1
Name
CKAN
Description
 
URL
https://catalogue.dev.cioosatlantic.ca